Influence of Ground Glass Opacity and the Corresponding Pathological Findings on Survival in Patients with Clinical Stage I Non–Small Cell Lung Cancer

Predicting Recurrence after Sublobar Resection in Patients with Lung Adenocarcinoma Using Preoperative Chest CT Scans

Background Sublobar resection for lung cancer is usually guided by cutoff values for consolidation size (maximal diameter of the solid tumor component) and consolidation-to-tumor ratio (CTR). The effects of these factors as continuous variables and the reason for established cutoffs are, to the knowledge of the authors, unexplored. Purpose To quantitatively assess the predictive value of CTR and consolidation size for cancer recurrence risk after sublobar resection in clinical stage IA lung adenocarcinoma. Materials and Methods This retrospective study reviewed sublobar resection for clinical stage IA lung adenocarcinoma performed between January 2010 and December 2019. A restricted cubic spline function verified linearity by estimating recurrence probabilities using CTR and consolidation size obtained on preoperative CT scans. Statistical analyses included a Cox proportional hazards model to identify risk factors for cancer recurrence and the Cochran-Armitage trend test for the association between CTR and consolidation size. Results Of 1032 enrolled patients (age, 63.9 years ± 9.9 [SD]; 464 male patients), 523 (50.7%) and 509 (49.3%) underwent wedge resection and segmentectomy, respectively. Among patients with a CTR between 1% and 50% (n = 201), 187 (93.0%) had a consolidation size of less than or equal to 10 mm (P < .001). There was a positive association between the risk of recurrence with CTR and consolidation size (r2 = 0.727; P < .001). The recurrence rate showed the greatest increase when CTR was greater than 50% or consolidation size was greater than 10 mm. Specifically, the recurrence rate increased from 2.1% (three of 146) at 26%-50% CTR to 8.3% (nine of 108) at 51%-75% CTR, and from 4.4% (eight of 183) for 6-10-mm consolidation size to 11.9% (23 of 194) for 11-15-mm consolidation size. The probability of recurrence exhibited linearity and increased with CTR and consolidation size. Conclusion Cancer recurrence risk after sublobar resection for stage IA adenocarcinoma consistently rises with CTR and consolidation size. Current guideline cutoffs for sublobar resection remain clinically relevant given observed recurrence rates. © RSNA, 2024 Supplemental material is available for this article.

Identification of the Prognostic Factors for Synchronous Multiple Primary Lung Cancer Treated With Staged Bilateral Surgery

INTRODUCTION

Staged bilateral surgery is widely used to treat synchronous multiple primary lung cancer (SMPLC); however, the prognostic factors for survival outcomes remain unclear. This study aimed to identify prognostic factors and construct a predictive model for overall survival (OS) and recurrence-free survival (RFS) in patients with SMPLC who underwent staged bilateral surgery.

METHODS

The study included 256 patients diagnosed with SMPLC and treated with staged bilateral surgery at our hospital between January 2010 and July 2017. Multivariate Cox proportional-hazard regression was used to identify prognostic factors for OS and RFS. Additionally, a predictive model was constructed using time-dependent receiver operating characteristic curves.

RESULTS

Among the 256 patients, 10 (3.95%) succumbed to the disease and 24 (9.41%) experienced recurrence. Smoking (hazard ratio [HR]: 5.128; 95% confidence interval [CI]: 1.442-18.233; p = 0.012) and most advanced pathological TNM (pTNM) stage (II + III) (HR: 12.938; 95% CI: 2.650-63.176; p = 0.002) were identified as significant predictors of poor OS. A prognostic model was developed for predicting OS, with a 5-year area under the curve (AUC) of 0.854. Furthermore, most advanced pTNM stage (II + III) was associated with poor RFS (HR: 5.964; 95% CI: 2.669-13.327; p < 0.001), and the predictive model exhibited a 5-year AUC of 0.718 for RFS.

CONCLUSION

This study revealed that smoking and most advanced pTNM stage were independent prognostic factors associated with poor OS in patients with bilateral SMPLC. Moreover, most advanced pTNM stage was also linked to unfavorable RFS. The developed predictive model demonstrated moderate prognostic performance for both OS and RFS.

Oncological characteristics of epidermal growth factor receptor-mutated clinical stage IA lung adenocarcinoma with radiologically pure-solid appearance

OBJECTIVES

We evaluated the clinicopathological and oncological characteristics of epidermal growth factor receptor-mutated clinical stage IA radiological pure-solid lung adenocarcinoma and compared them with those of a ground-glass opacity component.

METHODS

Between 2008 and 2020, data from 1014 surgically resected clinical stage 0-IA epidermal growth factor receptor-mutated lung adenocarcinomas were evaluated. Oncological outcomes were assessed using multivariable analysis. Overall survival was estimated using Kaplan-Meier analysis and the log-rank test. The cumulative incidence of recurrence was estimated using the Gray's test.

RESULTS

Of these, 233 (23%) were radiologically pure-solid tumors, which demonstrated a higher proportion of nodal metastasis, micropapillary component, spread through alveolar space, and Ex19 subtype compared with those of tumors with ground-glass opacity (P < .001). Multivariable analysis revealed that the presence of ground-glass opacity was an independently significant factor for overall survival (P = .037) and cumulative incidence of recurrence (P < .001). In cases where the oncological outcomes were stratified by the presence of ground-glass opacity component, the 5-year overall survival was excellent at more than 90% in tumors with ground-glass opacity despite clinical-T categories (P = .2044); however, tumor size significantly affected survival only in pure-solid tumors (T1a, 100%; T1b, 77.7%; T1c, 68.5%; P = .0056). Furthermore, the cumulative incidence of recurrence was low in tumors with ground-glass opacity despite the clinical-T categories, whereas tumor size significantly affected the cumulative incidence of recurrence only in pure-solid tumors (5-year cumulative incidence of recurrence: T1a-b, 18.9%; T1c, 41.3%; P < .001).

CONCLUSIONS

Oncologic behavior and prognosis of radiologically pure-solid tumors were significantly poorer than those of tumors with ground-glass opacity among patients with epidermal growth factor receptor-mutated early-stage lung adenocarcinoma. These findings imply distinct tumorigenesis based on the presence of ground-glass opacity, even in tumors with epidermal growth factor receptor mutations.

Long-term outcomes of 5-year survivors without recurrence after the complete resection of non-small cell lung cancer after lobectomy: a landmark analysis in consideration of competing risks

PURPOSE

Among non-small cell lung cancers (NSCLC), 5 years is a benchmark in cancer control and treatment, but a certain percentage of cases recur after 5 years. The long-term post-recurrence outcomes remain controversial. To examine the accurate prognostic factors associated with survival and cancer recurrence among 5-year survivors, a landmark analysis that considered competing risks was performed.

METHODS

Complete resection of NSCLC was performed in 2482 patients between January 2003 and December 2015. A total of 1431 patients were 5-year survivors without recurrence. A landmark time analysis was applied to the overall survival (OS) and recurrence-free survival (RFS) from 5 years after surgery, and the findings were calculated using the Kaplan-Meier method. The cumulative incidence of cause-specific death and recurrence was estimated using the cumulative incidence function, while carefully considering the competing risks.

RESULTS

Postoperative recurrence was detected in 732 patients, of whom 68 (9.3%) had recurrence after 5 years. The median follow-up period was 8.2 years. In the competing risk analysis, the independent poor prognostic factors associated with cause-specific death were age ≥ 75 years, lymph node metastasis and pleural invasion.

CONCLUSIONS

Patients requiring a follow-up for > 5 years were aged ≥ 75 years and had either lymph node metastasis or pleural invasion.

Evaluating the necessity of lymph node sampling in lung adenocarcinoma with ground glass opacities

BACKGROUND

Ground glass opacity is observed frequently in the early stages of lung adenocarcinoma and is associated with a favorable prognosis and a low incidence of lymph node metastasis. However, the necessity of lymph node sampling in these patients is questionable, although current guidelines still recommend it.

METHODS

Radiologic and clinical data were retrospectively collected and analyzed for 2,298 patients with lung cancer who underwent surgical resection for lesions ≤15 mm during 2022. Based on the consolidation tumor ratios, patients were categorized into 4 groups (pure ground glass opacity, ground glass opacity-predominant, solid-predominant, and pure solid). The incidence of lymph node metastasis in each group was examined.

RESULTS

A total of 2,298 patients with a median age of 54.0 years were enrolled in this study. Tumors were categorized into 4 types: 1,427 (62.1%) were pure ground glass opacity, which constituted the majority, while 421 (18.3%) were ground glass opacity-predominant, 330 (14.4%) were solid-predominant, and the remaining 120 (5.2%) were pure solid. Significant positive correlations were revealed between the consolidation tumor ratio group and pathologic grade (P < .001, ρ = 0.307), T stage (P < .001, ρ = 0.270), and N stage (P < .001, ρ = 0.105). Among the included cases, only 7 cases with metastasis were in the pure solid group. Within this group, 113 cases (94.2%) were N0, 5 cases (4.2%) were N1, and 2 cases (1.7%) were N2.

CONCLUSION

Lymph node metastasis exclusively occurred in the pure solid group, suggesting that for nodules <15 mm, lymph node sampling may be crucial for pure solid nodules but less so for those containing ground glass opacities.

The Simultaneous Bilateral Surgical Procedure for Bilateral Primary Lung Cancer

Objective: At present, the incidence of synchronous multiple primary lung cancer (SMPLC) is increasing, and the treatment is still a challenge. This study aims to investigate the appropriate surgical procedure for treating bilateral primary lung cancer simultaneously. Methods: A retrospective analysis was conducted on clinical data from 32 patients who underwent simultaneous bilateral lung cancer surgery in our team. This data included patient characteristics, pulmonary function indicators, surgical procedures, operation duration, chest tube removal time, postoperative hospital stay, and postoperative complications. Results: Out of the 32 patients, 15 were male, and 17 were female, with an average age of 56.4 ± 8.8 years. The average maximum diameter of the main and minor tumors was 1.8 ± 1.0 cm and 1.0 ± .5 cm, respectively. All surgeries were performed thoracoscopically through intercostal approach. The procedure for the minor tumor was performed first, followed by the main tumor operation after turning over. One case was converted to thoracotomy during the main tumor operation because of bleeding. Postoperative complications occurred in one patient. No instances of respiratory insufficiency or failure were observed after the operation, and there were no perioperative deaths or readmissions within 90 days. Conclusion: Simultaneous bilateral thoracoscopic surgery is deemed a secure and feasible option for eligible patients with bilateral primary lung cancer, and it is advisable to commence the operation on the minor tumor first.

Long-term outcomes and risk factors for recurrence after lung segmentectomy

OBJECTIVES

The long-term oncological outcomes and risk factors for recurrence after lung segmentectomy are unclear. The aims of this study were to investigate the long-term prognosis and to evaluate risk factors for recurrence after segmentectomy.

METHODS

Between January 2008 and December 2012, a total of 177 patients underwent segmentectomy for clinical stage I non-small cell lung cancer. The median follow-up period was 120.1 months. The overall survival (OS) and recurrence-free survival curves were analysed using the Kaplan-Meier method with a log-rank test. Univariable and multivariable analyses were used to identify significant factors that predicted recurrence.

RESULTS

The study included 177 patients with a median age of 67 years. The median operative time was 155 min. No 30-day deaths were observed. Nine patients (5.1%) had recurrences: loco-regional in 3, distant in 3 and both in 3. The 5-year and 10-year recurrence-free survival rates were 89.7% and 79.8%, and the OS rates were 90.9% and 80.4%, respectively. On multivariable analysis, the risk factor associated with recurrence was a pure solid tumour [hazard ratio, 23.151; 95% confidence interval 2.575-208.178; P = 0.005]. The non-pure solid tumour group had a significantly better probability of survival (5-year OS: 95.4% vs 77.2%; 10-year OS: 86.5% vs 61.8%; P < 0.0001). A total of 113 patients received preoperative positron emission tomography/computed tomography. Patients with a higher maximum standardized uptake value had a significantly higher recurrence rate.

CONCLUSIONS

Segmentectomy for clinical stage I non-small cell lung cancer produced acceptable long-term outcomes. Pure solid radiographic appearance was associated with recurrence and decreased survival.

AI-driven Characterization of Solid Pulmonary Nodules on CT Imaging for Enhanced Malignancy Prediction in Small-sized Lung Adenocarcinoma

OBJECTIVES

Distinguishing solid nodules from nodules with ground-glass lesions in lung cancer is a critical diagnostic challenge, especially for tumors ≤2 cm. Human assessment of these nodules is associated with high inter-observer variability, which is why an objective and reliable diagnostic tool is necessary. This study focuses on artificial intelligence (AI) to automatically analyze such tumors and to develop prospective AI systems that can independently differentiate highly malignant nodules.

MATERIALS AND METHODS

Our retrospective study analyzed 246 patients who were diagnosed with negative clinical lymph node metastases (cN0) using positron emission tomography-computed tomography (PET/CT) imaging and underwent surgical resection for lung adenocarcinoma. AI detected tumor sizes ≤2 cm in these patients. By utilizing AI to classify these nodules as solid (AI_solid) or non-solid (non-AI_solid) based on confidence scores, we aim to correlate AI determinations with pathological findings, thereby advancing the precision of preoperative assessments.

RESULTS

Solid nodules identified by AI with a confidence score ≥0.87 showed significantly higher solid component volumes and proportions in patients with AI_solid than in those with non-AI_solid, with no differences in overall diameter or total volume of the tumors. Among patients with AI_solid, 16% demonstrated lymph node metastasis, and a significant 94% harbored invasive adenocarcinoma. Additionally, 44% were upstaging postoperatively. These AI_solid nodules represented high-grade malignancies.

CONCLUSION

In small-sized lung cancer diagnosed as cN0, AI automatically identifies tumors as solid nodules ≤2 cm and evaluates their malignancy preoperatively. The AI classification can inform lymph node assessment necessity in sublobar resections, reflecting metastatic potential.

Diagnosis and treatment of high-risk bilateral lung ground-glass opacity nodules

In recent years, there has been a significant increase in the detection rate of Ground Glass Opacity (GGO) nodules through high-resolution computed tomography (HRCT). GGO is an imaging finding that encompasses various pathological types, some of which exhibit indolent growth, while others may represent early lung cancer or remain relatively stable, not significantly impacting the surgical treatment outcome. In clinical practice, patients often experience psychological anxiety when multiple pulmonary GGO nodules are present, and they may request simultaneous resection. However, there is currently no standardized criterion for determining when multiple GGO nodules should be resected. As personalized medicine continues to advance, the treatment approach for multiple pulmonary GGO nodules needs to prioritize accuracy. High-risk factors associated with multiple pulmonary GGO nodules may necessitate surgical intervention along with mediastinal lymph node dissection or sampling. This article provides a review of the characteristics, treatment methods, and clinical experiences related to multiple pulmonary GGO nodules, offering practical insights and guidance for healthcare professionals.

Transbronchial cryoablation in peripheral lung parenchyma with a novel thin cryoprobe and initial clinical testing

BACKGROUND

Transbronchial cryoablation shows potential as a local therapy for inoperable peripheral lung cancer. However, its clinical application for peripheral pulmonary lesions has not been reported yet.

METHODS

An improved cryoprobe with an 8-mm-long, 1.9-mm-wide cryotip was used. Initially, the safety and effectiveness of this cryoprobe were assessed in an in vivo porcine model. Transbronchial cryoablation with 2 or 3 freeze-thaw cycles (10 min or 15 min in each freezing time) was performed in 18 pigs under CT monitoring. Radiological and pathological examinations were performed to evaluate the extent of cryoablation. Subsequently, nine patients with stage IA peripheral lung cancer or metastases underwent transbronchial cryoablation with this cryoprobe under the guidance of navigation bronchoscopy and cone-beam CT. Technical success, safety and outcomes were assessed.

RESULTS

36 cryoablation procedures were performed successfully without any major complications in the porcine model. The extent of cryoablation increased with freezing time and the number of freeze-thaw cycles, which peaked at 24 hours and then gradually decreased. Pathological results showed a change from massive haemorrhage at 24 hours to fibrous hyperplasia with chronic inflammation after 4 weeks. In the clinical trial, 10 cryoablations were performed on 9 tumours with a technical success rate of 100%. One mild treatment-related complication occurred. Of the nine tumours, seven achieved complete ablation, while two exhibited incomplete ablation and subsequent local progression at 6 months.

CONCLUSION

Our initial experience indicated that transbronchial cryoablation was a safe and feasible procedure for non-surgical peripheral stage IA lung cancer or pulmonary metastases.

TRIAL REGISTRATION NUMBER

ChiCTR2200061544.

A Multi-Institutional, Randomized, Phase III Trial Comparing Anatomical Segmentectomy and Lobectomy for Clinical Stage IA3 Pure-Solid Non-Small-Cell Lung Cancer: West Japan Oncology Group Study WJOG16923L (STEP UP Trial)

INTRODUCTION

Although the standard treatment for patients with resectable early-stage non-small-cell lung cancer (NSCLC) is pulmonary lobectomy, recent clinical trials have demonstrated the efficacy of anatomical segmentectomy for small-sized early-stage NSCLC measuring ≤2 cm. Segmentectomy is gaining attention as an alternative procedure to lobectomy for early-stage NSCLC.

PATIENTS AND METHODS

In January 2024, we have initiated a randomized phase III trial in Japan to confirm the noninferiority of anatomical segmentectomy to lobectomy in patients with peripheral clinical stage IA3 pure-solid NSCLC (tumor measuring >2 cm and ≤3 cm; consolidation-to-tumor ratio = 1.0). We plan to enroll 520 patients from 61 institutions over a period of 5 years. The primary endpoint is overall survival, and the secondary endpoints include relapse-free survival, postoperative respiratory function, proportion of patients with respiratory failure and cerebrovascular disease, cumulative incidence of death from other diseases, cumulative incidence of local recurrence, proportion of patients who undergo segmentectomy, number of resected segments, operative time, blood loss, and adverse events. This trial has been registered in the UMIN Clinical Trials Registry under the code UMIN000052064.

CONCLUSIONS

This trial will help establish a novel treatment strategy for patients with peripheral clinical stage IA3 pure-solid NSCLC.

Prognostic implications of CT-defined ground glass opacity in clinical stage I-IIA grade 3 invasive non-mucinous pulmonary adenocarcinoma

AIM

To investigate the prognostic impact of computed tomography (CT)-defined ground glass opacity (GGO) in patients with clinical stage I-IIA grade 3 invasive non-mucinous pulmonary adenocarcinoma (INPA).

MATERIALS AND METHODS

The present study retrospectively enrolled 187 patients diagnosed with stage I-IIA grade 3 INPA. Their clinicopathological, radiological, and genetic information was evaluated systematically, and a 5-year follow-up was conducted to monitor disease recurrence and mortality. Patients were stratified based on the presence of a GGO component, and the Cox proportional hazard model was employed to assess the influence of clinicopathological factors and genetic variables on tumour outcomes. Recurrence-free survival (RFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Significant differences were observed in both OS and RFS based on the presence of a GGO component. The group with GGO exhibited superior OS (p=0.002) and RFS (p=0.029). Multivariate analysis revealed that the presence of a GGO component (hazard ratio [HR] = 0.412, 95% confidence interval [CI]: 0.177-0.959, p=0.040), clinical T2 stage (HR=2.473, 95% CI: 1.498-4.083, p<0.001), pathological N2 stage (HR=3.049, 95% CI: 1.800-5.167, p<0.001), and mixed high-grade patterns (HR=2.392, 95% CI: 1.418-4.036, p=0.001) were predictors of RFS.

CONCLUSION

The presence of a GGO component is strongly associated with a favourable prognosis in grade 3 INPA.

Clinical Significance of the Proposed Pathologic Criteria for Invasion by the International Association for the Study of Lung Cancer in Resected Nonmucinous Lung Adenocarcinoma

INTRODUCTION

Accurate diagnostic criteria for tumor invasion are essential for precise pathologic tumor (pT) staging. Recently, the International Association for the Study of Lung Cancer (IASLC) Pathology Committee suggested a new set of criteria for assessing tumor invasion, but the clinical usefulness of the proposed criteria has not been evaluated.

METHODS

The study included 1295 patients with resected part-solid lung adenocarcinoma from January 2017 to December 2019 at the Samsung Medical Center, Seoul, Korea. The revised pT stage was determined by the extent of the newly measured invasive component using the IASLC criteria. The primary outcome was to compare the performance of the revised pT stage with the original pT stage in predicting recurrence-free survival and proof of invasion status (i.e., recurrence or lymph node metastasis). The secondary outcome was the correlation with radiologic surrogates of tumor invasiveness (consolidation-to-tumor ratio and maximum standardized uptake value) and pathologic risk factors.

RESULTS

The re-evaluation resulted in a 22% downstaging and 2.5% upstaging of pT, which improved the correlation with radiologic (consolidation-to-tumor ratio and maximum standardized uptake value) and pathologic risk factors. The revised pT staging allowed for more accurate discrimination of recurrence-free survival than the original pT staging (c-index = 0.794 versus 0.717). Moreover, the revised pT staging significantly improved the prediction of recurrence or lymph node metastasis (area under the curve = 0.818 versus 0.741, p < 0.001).

CONCLUSIONS

To our knowledge, this is the first study evaluating the clinical significance of the IASLC-proposed criteria for invasion. The proposed IASLC criteria offered better alignment with clinicopathologic risk factors and improved prognostication. Further studies are warranted to assess the impact of the IASLC criteria on treatment decisions and patient outcomes.

Predictors of residual simultaneous multiple ground-glass nodule progression after dominant lesion resection

OBJECTIVE

This study aimed to identify the predictive factors for the progression of residual simultaneous multifocal ground-glass nodules (SMGGNs) after resection of the dominant lesion.

METHODS

Patients (n = 3420) with primary lung cancer who underwent lung resections at our hospital between 2006 and 2016 were screened, and the data from 82 patients who had residual SMGGNs after undergoing surgery for the dominant lesion (pathologically stage 0-IIA) were retrospectively analyzed. Clinicopathological factors that predicted the growth of residual second dominant GGNs were identified.

RESULTS

Median total tumor and solid component sizes of the residual second dominant GGNs were 1.3 cm (interquartile range [IQR]: 0.6-2.0) and 0 cm (IQR: 0-0.7), respectively. During a median follow-up period of 54 months (IQR: 37-78 months), 35 (43%) lesions progressed. Logistic regression analysis revealed that age younger than 70 (OR: 10.54, 95% CI: 1.71-65.11), a dominant lesion with pure solid appearance (reference: GGN, OR: 18.16, 95% CI: 1.66-198.60), a second dominant GGN total size larger than 1.0 cm (OR: 12.27, 95% CI: 1.85-81.17), and a second dominant GGN solid component size larger than 0.5 cm (OR: 17.59, 95% CI: 3.58-86.47) were significant predictive factors for the progression of residual GGNs (all p values < 0.03). Based on an analysis of growth patterns, rapid growth was higher in second dominant GGNs with a part-solid appearance.

CONCLUSIONS

If the resected dominant lesion or the residual second dominant GGN exhibits high-risk factors, the second dominant GGN should be meticulously observed.

Prognostic value of CT-defined ground-glass opacity in early-stage lung adenocarcinomas: a single-center study and meta-analysis

OBJECTIVES

The prognostic value of ground-glass opacity at preoperative chest CT scans in early-stage lung adenocarcinomas is a matter of debate. We aimed to clarify the existing evidence through a single-center, retrospective cohort study and to quantitatively summarize the body of literature by conducting a meta-analysis.

METHODS

In a retrospective cohort study, patients with clinical stage I lung adenocarcinoma were identified, and the prognostic value of ground-glass opacity was analyzed using multivariable Cox regression. Commercial artificial intelligence software was adopted as the second reader for the presence of ground-glass opacity. The primary end points were freedom from recurrence (FFR) and lung cancer-specific survival (LCSS). In a meta-analysis, we systematically searched Embase and OVID-MEDLINE up to December 30, 2021, for the studies based on the eighth-edition staging system. The pooled hazard ratios (HRs) of solid nodules (i.e., absence of ground-glass opacity) for various end points were calculated with a multi-level random effects model.

RESULTS

In a cohort of 612 patients, solid nodules were associated with worse outcomes for FFR (adjusted HR, 1.98; 95% CI: 1.17-3.51; p = 0.01) and LCSS (adjusted HR, 1.937; 95% CI: 1.002-4.065; p = 0.049). The artificial intelligence assessment and multiple sensitivity analyses revealed consistent results. The meta-analysis included 13 studies with 12,080 patients. The pooled HR of solid nodules was 2.13 (95% CI: 1.69-2.67; I2 = 30.4%) for overall survival, 2.45 (95% CI: 1.52-3.95; I2 = 0.0%) for FFR, and 2.50 (95% CI: 1.28-4.91; I2 = 30.6%) for recurrence-free survival.

CONCLUSIONS

The absence of ground-glass opacity in early-stage lung adenocarcinomas is associated with worse postoperative survival.

CLINICAL RELEVANCE STATEMENT

Early-stage lung adenocarcinomas manifesting as solid nodules at preoperative chest CT, which indicates the absence of ground-glass opacity, were associated with poor postoperative survival. There is room for improvement of the clinical T categorization in the next edition staging system.

KEY POINTS

• In a retrospective study of 612 patients with stage I lung adenocarcinoma, solid nodules were associated with shorter freedom from recurrence (adjusted hazard ratio [HR], 1.98; p = 0.01) and lung cancer-specific survival (adjusted HR, 1.937; p = 0.049). • Artificial intelligence-assessed solid nodules also showed worse prognosis (adjusted HR for freedom from recurrence, 1.94 [p = 0.01]; adjusted HR for lung cancer-specific survival, 1.93 [p = 0.04]). • In meta-analyses, the solid nodules were associated with shorter freedom from recurrence (HR, 2.45) and shorter overall survival (HR, 2.13).

Incorporation of the lepidic component as an additional pathological T descriptor for non-small cell lung cancer: Data from 3335 cases of lung adenocarcinoma

OBJECTIVES

The Lepidic Component (LP) identifies a subgroup with an excellent prognosis for lung adenocarcinoma (LUAD). Our research aimed to propose an improved pathological T (pT) stage for LUAD based on LP.

MATERIALS AND METHODS

Totally, 3335 surgical patients with pathological stage I LUAD were incorporated. Factors affecting survival were investigated by analyzing recurrence-free survival (RFS) and overall survival (OS) using the Kaplan-Meier method and Cox regression analyses. Subgroup analysis based on Lepidic Ratio (LR) was further evaluated. The net benefit from the modified pT category (pTm) was assessed using the Area Under the time-dependent Receiver Operating Curve (AUC), Harrell's Concordance Index (C-index), Reclassification Improvement (NRI), and Integrated Discrimination Improvement (IDI).

RESULTS

The presence of LP (LP+) was identified in 1425 (42.7 %) patients, indicating a significantly better RFS (P < 0.001) and OS (P < 0.001) than those without LP, and similar results were reproduced in pT1a-pT2a subcategory (P < 0.050 for all). Multivariable Cox analysis revealed LP+ as an independent prognostic factor for both RFS (HR, 0.622; P < 0.001) and OS (HR, 0.710; P = 0.019). However, lepidic ratio (LR) was not independently associated with both RFS and OS for LP+ patients. The 5-year RFS and OS rates between T1a (LP-) and T1b (LP+), T1b (LP-) and T1c (LP+), and T1b (LP-) and T2a (LP+) were comparable (P > 0.050 for all). After modification, compared with current 8th edition pT stage system (pT8), pTm independently predicted RFS and OS, and AUCs, c-index, NRI, and IDI analysis all demonstrated pTm holds better discrimination performances than pT8 for LUAD prognosis.

CONCLUSION

LP can be an additional down-staged T descriptor for pathological stage I LUAD and improve the survival predictive performance of reclassification.

Multiparametric evaluation of mediastinal lymph node metastases in clinical T0-T1c stage non-small-cell lung cancers

OBJECTIVES

This study aimed to determine the predictive factors of lymph node metastases in clinical T0-T1c stage non-small-cell lung cancers, so as to help making surgical strategy.

METHODS

From January 2016 to December 2017, patients with clinical T0-T1c stage non-small-cell lung cancers were retrospectively reviewed. We elucidated the lymph node metastatic incidence and distribution according to the primary tumour radiographic findings and maximal standard uptake values, and extracted the associated clinicopathological factors. Univariable and multivariable logistic regressions were used to identify independent predictive parameters for lymph node metastases. The performance of predictive model was evaluated using receiver operating characteristic analysis.

RESULTS

A total of 517 patients were included. Seventy-two patients had lymph node metastases. Among patients with pure ground-glass nodule and solid component size ≤10 mm, none had any lymph node metastasis. Multivariable logistic regression analysis demonstrated that age, carcinoembryonic antigen level, solid component size, consolidation-tumour ratio and tumour maximal standard uptake values were independent predictors of lymph nodal metastases. Receiver operating characteristic analyses indicated that the area under the curve of predictive model in evaluating lymph node metastases was 0.838 (95% CI 0.791-0.886).

CONCLUSIONS

Younger age, elevated carcinoembryonic antigen level, larger solid component size, higher consolidation-tumour ratio and tumour maximal standard uptake values were associated with lymph node involvement. Employing such a predictive model in the future may affect the surgical option of lymph node excision for patients in cT1 stage non-small-cell lung cancer.

Segmentectomy versus lobectomy in small-sized peripheral non-small-cell lung cancer with radiologically pure-solid appearance in Japan (JCOG0802/WJOG4607L): a post-hoc supplemental analysis of a multicentre, open-label, phase 3 trial

BACKGROUND

Although segmentectomy was better than lobectomy in terms of overall survival for patients with non-small-cell lung cancer (NSCLC) with a pure-solid tumour appearance on thin-section CT in the open-label, multicentre, randomised, controlled, phase 3 JCOG0802/WJOG4607L trial, the reasons why segmentectomy was associated with better overall survival were unclear. We aimed to compare the survival, cause of death, and recurrence patterns after segmentectomy versus lobectomy in trial participants with NSCLC with a pure-solid appearance METHODS: We conducted a post-hoc supplemental analysis of the JCO0802/WJOG4607L randomised, controlled, non-inferiority trial for the patients (aged 20-85 years) with small-sized NSCLC with radiologically pure-solid appearance on thin-section CT (≤2 cm, consolidation tumour ratio 1·0). The primary aim was to compare the overall and relapse-free survival, cause of death, and recurrence patterns associated with segmentectomy and lobectomy for patients with radiologically pure-solid NSCLC to determine why the overall survival of segmentectomy was superior to that of lobectomy, even for oncologically invasive lung cancers. JCO0802/WJOG4607L is registered with the UMIN Clinical Trials Registry, UMIN000002317, and is complete.

FINDINGS

Between Aug 10, 2009, and Oct 21, 2014, 1106 patients were randomly assigned to undergo either lobectomy or segmentectomy. Of these participants, 553 (50%) had radiologically pure-solid NSCLC and were eligible for this post-hoc supplemental analysis. Of these 553 participants, 274 (50%) patients underwent lobectomy and 279 (50%) underwent segmentectomy. Median patient age was 67 years (IQR 61-73), 347 (63%) of 553 patients were male and 206 (37%) were female, and data on race and ethnicity were not collected. As of data cutoff (June 13, 2020), after a median follow-up of 7·3 years (IQR 6·0-8·5), the 5-year overall survival rate was significantly higher after segmentectomy than after lobectomy (86·1% [95% CI 81·4-89·7] in the lobectomy group, with 55 deaths vs 92·4% [88·6-95·0] in the segmentectomy group, with 38 deaths; hazard ratio (HR) 0·64 [95% CI 0·41-0·97]; log-rank test p=0·033), whereas the 5-year relapse-free survival was similar between the groups (81·7% [95% CI 76·5-85·8], with 34 events vs 82·0% [76·9-86·0], with 52 events; HR 1·01 [95% CI 0·72-1·42]; p=0·94). Deaths after a median follow-up of 7·3 years due to lung cancer occurred in 20 (7%) of 274 patients after lobectomy and 19 (7%) of 279 after segmentectomy, and deaths due to other causes occurred in 35 (13%) patients after lobectomy compared with 19 (7%) after segmentectomy (lung cancer death vs other cause of death, p=0·19). The locoregional recurrence was higher after segmentectomy (21 [8%] vs 45 [16%]; p=0·0021). In subgroup analyses, better 5-year overall survival after segmentectomy than after lobectomy was observed in the subgroup of patients aged 70 years or older (77·1% [95% CI 68·2-83·8] with lobectomy vs 85·6% [77·5-90·9] with segmentectomy; p=0·013) and in male patients (80·5% [73·7-85·7] vs 92·1% [87·0-95·2]; p=0·0085). By contrast, better 5-year relapse-free survival after lobectomy than after segmentectomy was observed in the subgroup younger than 70 years (87·4% [95% CI 81·2-91·7] with lobectomy vs 84·4% [77·9-89·1] with segmentectomy; p=0·049) and in female patients (94·2% [87·6-97·4] vs 82·2% [73·2-88·4]; p=0·047).

INTERPRETATION

This post-hoc analysis showed improved overall survival after segmentectomy in patients with pure-solid NSCLC compared with lobectomy. However, survival outcomes of segmentectomy depend on the patient's age and sex. Given the results of this exploratory analysis, further research is necessary to determine clinically relevant indications for segmentectomy in radiologically pure-solid NSCLC.

FUNDING

Japanese National Cancer Center Research and Development Fund and Practical Research for Innovative Cancer Control Fund, and a Grant-in-Aid for Scientific Research from the Ministry of Health, Labor, and Welfare of Japan.

Evaluation of Prognosis in Patients with Lung Adenocarcinoma with Atypical Solid Nodules on Thin-Section CT Images

Purpose To evaluate the clinicopathologic characteristics and prognosis of patients with clinical stage IA lung adenocarcinoma with atypical solid nodules (ASNs) on thin-section CT images. Materials and Methods Data from patients with clinical stage IA lung adenocarcinoma who underwent resection between January 2005 and December 2012 were retrospectively reviewed. According to their manifestations on thin-section CT images, nodules were classified as ASNs, subsolid nodules (SSNs), and typical solid nodules (TSNs). The clinicopathologic characteristics of the ASNs were investigated, and the differences across the three groups were analyzed. The Kaplan-Meier method and multivariable Cox analysis were used to evaluate survival differences among patients with ASNs, SSNs, and TSNs. Results Of the 254 patients (median age, 58 years [IQR, 53-66]; 152 women) evaluated, 49 had ASNs, 123 had SSNs, and 82 had TSNs. Compared with patients with SSNs, those with ASNs were more likely to have nonsmall adenocarcinoma (P < .001), advanced-stage adenocarcinoma (P = .004), nonlepidic growth adenocarcinoma (P < .001), and middle- or low-grade differentiation tumors (P < .001). Compared with patients with TSNs, those with ASNs were more likely to have no lymph node involvement (P = .009) and epidermal growth factor receptor mutation positivity (P = .018). Average disease-free survival in patients with ASNs was significantly longer than that in patients with TSNs (P < .001) but was not distinguishable from that in patients with SSNs (P = .051). Conclusion ASNs were associated with better clinical outcomes than TSNs in patients with clinical stage IA lung adenocarcinoma. Keywords: Adenocarcinoma, Atypical Solid Nodules, CT, Disease-free Survival, Lung, Prognosis, Pulmonary Supplemental material is available for this article. Published under a CC BY 4.0 license.

Measurement of solid size in early-stage lung adenocarcinoma by virtual 3D thin-section CT applied artificial intelligence

An artificial intelligence (AI) system that reconstructs virtual 3D thin-section CT (TSCT) images from conventional CT images by applying deep learning was developed. The aim of this study was to investigate whether virtual and real TSCT could measure the solid size of early-stage lung adenocarcinoma. The pair of original thin-CT and simulated thick-CT from the training data with TSCT images (thickness, 0.5-1.0 mm) of 2700 pulmonary nodules were used to train the thin-CT generator in the generative adversarial network (GAN) framework and develop a virtual TSCT AI system. For validation, CT images of 93 stage 0-I lung adenocarcinomas were collected, and virtual TSCTs were reconstructed from conventional 5-mm thick-CT images using the AI system. Two radiologists measured and compared the solid size of tumors on conventional CT and virtual and real TSCT. The agreement between the two observers showed an almost perfect agreement on the virtual TSCT for solid size measurements (intraclass correlation coefficient = 0.967, P < 0.001, respectively). The virtual TSCT had a significantly stronger correlation than that of conventional CT (P = 0.003 and P = 0.001, respectively). The degree of agreement between the clinical T stage determined by virtual TSCT and the clinical T stage determined by real TSCT was excellent in both observers (k = 0.882 and k = 0.881, respectively). The AI system developed in this study was able to measure the solid size of early-stage lung adenocarcinoma on virtual TSCT as well as on real TSCT.

Air bronchogram on chest CT in radiological pure-solid appearance lung cancer: Correlation analysis with genetic pathological features and survival outcomes

PURPOSE

To investigate the correlation of air bronchogram sign with clinicopathological characteristics and prognosis in patients with clinical stage (c-stage) I non-small cell lung cancer (NSCLC) with radiological pure-solid appearance.

METHOD

We retrospectively evaluated 276 patients with pure-solid c-stage I NSCLC and assessed the correlation between the air bronchogram and clinicopathological characteristics. A Cox proportional hazards model was performed to identify the effect of air bronchogram and clinicopathological variables on oncological outcomes. Recurrence-free survival (RFS) and overall survival (OS) were calculated by Kaplan-Meier curves and were compared using log-rank tests.

RESULTS

Presence of air bronchogram was associated with a well differentiated degree (P =.026), higher incidence of EGFR mutation (P <.001) and lower recurrence(P =.021). Kaplan-Meier survival curves showed that air bronchogram group was associated with favorable RFS(67.0% vs. 50.2%; P =.015). A multivariable analysis revealed that air bronchogram and EGFR mutation were independent significant prognostic factors associated with RFS (hazard ratio [HR] = 0.495, 95% confidence interval [CI]: 0.322-0.761, P =.001; HR = 1.625, 95% CI: 1.074-2.457, P =.021; respectively), but not with OS. Additionally, we found that pathological lymph node metastasis was identified as an independent prognostic factor associated with poor RFS and OS(HR = 2.808, 95% CI: 1.913-4.123, P <.001 for RFS; HR = 1.983, 95% CI: 1.185-3.318, P =.009 for OS).

CONCLUSIONS

Presence of air bronchogram was associated with well differentiated degree, higher incidence of EGFR mutation and had additional positive prognostic value for RFS in c-stage I NSCLC with a radiological pure-solid appearance.

Lack of incremental value of three-dimensional measurement in assessing invasiveness for lung cancer

OBJECTIVES

The aim of this study was to evaluate the performance of consolidation-to-tumour ratio (CTR) and the radiomic models in two- and three-dimensional modalities for assessing radiological invasiveness in early-stage lung adenocarcinoma.

METHODS

A retrospective analysis was conducted on patients with early-stage lung adenocarcinoma from Guangdong Provincial People's Hospital and Shenzhen People's Hospital. Manual delineation of pulmonary nodules along the boundary was performed on cross-sectional images to extract radiomic features. Clinicopathological characteristics and radiomic signatures were identified in both cohorts. CTR and radiomic score for every patient were calculated. The performance of CTR and radiomic models were tested and validated in the respective cohorts.

RESULTS

A total of 818 patients from Guangdong Provincial People's Hospital were included in the primary cohort, while 474 patients from Shenzhen People's Hospital constituted an independent validation cohort. Both CTR and radiomic score were identified as independent factors for predicting pathological invasiveness. CTR in two- and three-dimensional modalities exhibited comparable results with areas under the receiver operating characteristic curves and were demonstrated in the validation cohort (area under the curve: 0.807 vs 0.826, P = 0.059) Furthermore, both CTR in two- and three-dimensional modalities was able to stratify patients with significant relapse-free survival (P < 0.000 vs P < 0.000) and overall survival (P = 0.003 vs P = 0.001). The radiomic models in two- and three-dimensional modalities demonstrated favourable discrimination and calibration in independent cohorts (P = 0.189).

CONCLUSIONS

Three-dimensional measurement provides no additional clinical benefit compared to two-dimensional.

Oncologic outcomes of segmentectomy versus lobectomy for clinical T1c radiological pure-solid non-small-cell lung cancer

OBJECTIVES

We aimed to compare the outcomes of segmentectomy with those of lobectomy in T1c (>2-3 cm) radiological pure-solid non-small-cell lung cancer detected on thin-section computed tomography.

METHODS

This retrospective review compared the survival outcomes, causes of death and recurrence patterns between the segmentectomy and lobectomy in patients with c-T1cN0M0 radiological pure-solid non-small-cell lung cancer. Multivariable analysis was performed to control for confounders of survival. The overall survival (OS) and recurrence-free survival were analysed using the Kaplan-Meier method. Differences in cumulative incidence of recurrence between groups were assessed using the methods of Gray.

RESULTS

Of the 426 patients, lobectomy was performed in 381 patients and segmentectomy in 45 patients. Nodal metastasis was noted in 104 (24.4%) patients. Multivariable analysis revealed that lobectomy was an independent prognosticator of better OS (hazard ratio 0.596, 95% confidence interval 0.366-0.969; P = 0.037). Lobectomy arm showed favourable 5-year OS and recurrence-free survival (OS: 72.9% vs 59.7%, log-rank test P = 0.007; recurrence-free survival: 64.4% vs 48.7%, P = 0.034) (median follow-up: 53 months). Approximately 14% of the patients in the lobectomy group and 27% in the segmentectomy group died of lung cancer. Furthermore, 5-year cumulative incidence of loco-regional recurrence rate was significantly higher in the segmentectomy group (35.5% vs 15.8%, P < 0.001).

CONCLUSIONS

In T1c radiological pure-solid non-small-cell lung cancer, segmentectomy was significantly associated with worse survival and insufficient loco-regional cancer control. Lobectomy remains the standard surgical treatment; meanwhile, segmentectomy should be applied with great caution.

Segmentectomy for patients with early-stage pure-solid non-small cell lung cancer

For decades, lobectomy has been the recommended surgical procedure for non-small cell lung cancer (NSCLC), including for small-sized lesions. However, two recent pivotal clinical trials conducted by the Japanese Clinical Oncology Group/West Japan Oncology Group (JCOG0802/WJOG4607L) and the Cancer and Leukemia Group B (CALGB140503), which compared the survival outcomes between lobectomy and sublobar resection (the JCOG0802/WJOG4607L included only segmentectomy, not wedge resection), demonstrated the efficacy of sublobar resection in patients with early-stage peripheral lung cancer measuring ≤ 2 cm. The JCOG0802/WJOG4607L demonstrated the superiority of segmentectomy over lobectomy with respect to overall survival, implying the survival benefit conferred by preservation of the lung parenchyma. Subsequently, the JCOG1211 also demonstrated the efficacy of segmentectomy, even for NSCLC, measuring up to 3 cm with the predominant ground-glass opacity phenotype. Segmentectomy has become the standard of care for early-stage NSCLC and its indications are expected to be further expanded to include solid lung cancers > 2 cm. However, local control is still a major concern for segmentectomy for higher-grade malignant tumors. Thus, the indications of segmentectomy, especially for patients with radiologically pure-solid NSCLC, remain controversial due to the aggressive nature of the malignancy. In this study, we reviewed previous studies and discussed the efficacy of segmentectomy for patients with such tumors.

Mediastinal lymph node dissection versus spared mediastinal lymph node dissection in stage IA non-small cell lung cancer presented as ground glass nodules: study protocol of a phase III, randomised, multicentre trial (MELDSIG) in China

INTRODUCTION

Radical surgery including mediastinal lymph node dissection is the standard treatment for early-stage non-small cell lung cancer (NSCLC). About 50% lung nodules are pure ground glass or part-solid nodules, which are predominantly clinical stage IA NSCLC. Non-solid nodules rarely develop mediastinal lymph node metastasis.

METHOD AND ANALYSIS

A phase III study was started in China to evaluate the non-inferiority in overall survival of spared mediastinal lymph node dissection compared with mediastinal lymph node dissection in stage IA NSCLC. A total of 1362 patients will be enrolled from 4 institutions in 2-3 years. The second endpoints are relapse-free survival and perioperative data, including duration of hospitalisation, duration of chest tube placement, operation time, blood loss.

ETHICS AND DISSEMINATION

This protocol has been reviewed and approved by the Clinical Research Review Board of Tianjin Medical University Cancer Institute and Hospital. The findings will be disseminated in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT04631770.

A machine learning-based PET/CT model for automatic diagnosis of early-stage lung cancer

Objective

The aim of this study was to develop a machine learning-based automatic analysis method for the diagnosis of early-stage lung cancer based on positron emission tomography/computed tomography (PET/CT) data.

Methods

A retrospective cohort study was conducted using PET/CT data from 187 cases of non-small cell lung cancer (NSCLC) and 190 benign pulmonary nodules. Twelve PET and CT features were used to train a diagnosis model. The performance of the machine learning-based PET/CT model was tested and validated in two separate cohorts comprising 462 and 229 cases, respectively.

Results

The standardized uptake value (SUV) was identified as an important biochemical factor for the early stage of lung cancer in this model. The PET/CT diagnosis model had a sensitivity and area under the curve (AUC) of 86.5% and 0.89, respectively. The testing group comprising 462 cases showed a sensitivity and AUC of 85.7% and 0.87, respectively, while the validation group comprising 229 cases showed a sensitivity and AUC of 88.4% and 0.91, respectively. Additionally, the proposed model improved the clinical discrimination ability for solid pulmonary nodules (SPNs) in the early stage significantly.

Conclusion

The feature data collected from PET/CT scans can be analyzed automatically using machine learning techniques. The results of this study demonstrated that the proposed model can significantly improve the accuracy and positive predictive value (PPV) of SPNs at the early stage. Furthermore, this algorithm can be optimized into a robotic and less biased PET/CT automatic diagnosis system.

Differences of molecular events driving pathological and radiological progression of lung adenocarcinoma

BACKGROUND

Ground-glass opacity (GGO)-like lung adenocarcinoma (LUAD) has been detected increasingly in the clinic and its inert property and superior survival indicate unique biological characteristics. However, we do not know much about them, which hampers identification of key reasons for the inert property of GGO-like LUAD.

METHODS

Using whole-exome sequencing and RNA sequencing, taking into account both radiological and pathological classifications of the same 197 patients concomitantly, we systematically interrogate genes driving the progression from GGO to solid nodule and potential reasons for the inertia of GGO. Using flow cytometry and IHC, we validated the abundance of immune cells and activity of cell proliferation.

FINDINGS

Identifying the differences between GGO and solid nodule, we found adenocarcinoma in situ/minimally invasive adenocarcinoma (AIS/MIA) and GGO-like LUAD exhibited lower TP53 mutation frequency and less active cell proliferation-related pathways than solid nodule in LUAD. Identifying the differences in GGO between AIS/MIA and LUAD, we noticed that EGFR mutation frequency and CNV load were significantly higher in LUAD than in AIS/MIA. Regulatory T cell was also higher in LUAD, while CD8+ T cell decreased from AIS/MIA to LUAD. Finally, we constructed a transcriptomic signature to quantify the development from GGO to solid nodule, which was an independent predictor of patients' prognosis in 11 external LUAD datasets.

INTERPRETATION

Our results provide deeper insights into the indolent nature of GGO and provide a molecular basis for the treatment of GGO-like LUAD.

FUNDING

This study was supported in part by the National Natural Science Foundation of China (32170657), the National Natural Science Foundation of China (82203037), and Shanghai Sailing Program (22YF1408900).

Prognostic role of preoperative fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography with an image-based harmonization technique: A multicenter retrospective study

Objectives

Despite the prognostic impacts of preoperative fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography examination, fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography-based prognosis prediction has not been used clinically because of the disparity in data between institutions. By applying an image-based harmonized approach, we evaluated the prognostic roles of fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters in clinical stage I non-small cell lung cancer.

Methods

We retrospectively examined 495 patients with clinical stage I non-small cell lung cancer who underwent fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography examinations before pulmonary resection between 2013 and 2014 at 4 institutions. Three different harmonization techniques were applied, and an image-based harmonization, which showed the best-fit results, was used in the further analyses to evaluate the prognostic roles of fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters.

Results

Cutoff values of image-based harmonized fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters, maximum standardized uptake, metabolic tumor volume, and total lesion glycolysis were determined using receiver operating characteristic curves that distinguish pathologic high invasiveness of tumors. Among these parameters, only the maximum standardized uptake was an independent prognostic factor in recurrence-free and overall survivals in univariate and multivariate analyses. High image-based maximum standardized uptake value was associated with squamous histology or lung adenocarcinomas with higher pathologic grades. In subgroup analyses defined by ground-glass opacity status and histology or by clinical stages, the prognostic impact of image-based maximum standardized uptake value was always the highest compared with other fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters.

Conclusions

The image-based fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography harmonization was the best fit, and the image-based maximum standardized uptake was the most important prognostic marker in all patients and in subgroups defined by ground-glass opacity status and histology in surgically resected clinical stage I non-small cell lung cancers.

Recurrence Patterns and Patient Outcomes in Resected Lung Adenocarcinoma Differ according to Ground-Glass Opacity at CT

Background Although lung adenocarcinoma with ground-glass opacity (GGO) is known to have distinct characteristics, limited data exist on whether the recurrence pattern and outcomes in patients with resected lung adenocarcinoma differ according to GGO presence at CT. Purpose To examine recurrence patterns and associations with outcomes in patients with resected lung adenocarcinoma according to GGO at CT. Materials and Methods Patients who underwent CT followed by lobectomy or pneumonectomy for lung adenocarcinoma between July 2010 and December 2017 were retrospectively included. Patients were divided into two groups based on the presence of GGO: GGO adenocarcinoma and solid adenocarcinoma. Recurrence patterns at follow-up CT examinations were investigated and compared between the two groups. The effects of patient grouping on time to recurrence, postrecurrence survival (PRS), and overall survival (OS) were evaluated using Cox regression. Results Of 1019 patients (mean age, 62 years ± 9 [SD]; 520 women), 487 had GGO adenocarcinoma and 532 had solid adenocarcinoma. Recurrences occurred more frequently in patients with solid adenocarcinoma (36.1% [192 of 532 patients]) than in those with GGO adenocarcinoma (16.2% [79 of 487 patients]). Distant metastasis was the most common mode of recurrence in the group with solid adenocarcinoma and all clinical stages. In clinical stage I GGO adenocarcinoma, all regional recurrences appeared as ipsilateral lung metastasis (39.2% [20 of 51]) without regional lymph node metastasis. Brain metastasis was more frequent in patients with clinical stage I solid adenocarcinoma (16.5% [16 of 97 patients]). The presence of GGO was associated with time to recurrence and OS (adjusted hazard ratio [HR], 0.6 [P < .001] for both). Recurrence pattern was an independent risk factor for PRS (adjusted HR, 2.1 for distant metastasis [P < .001] and 3.9 for brain metastasis [P < .001], with local-regional recurrence as the reference). Conclusion Recurrence patterns, time to recurrence, and overall survival differed between patients with and without ground-glass opacity at CT, and recurrence patterns were associated with postrecurrence survival. © RSNA, 2023 Supplemental material is available for this article.

Segmentectomy for ground-glass-dominant lung cancer with a tumour diameter of 3 cm or less including ground-glass opacity (JCOG1211): a multicentre, single-arm, confirmatory, phase 3 trial

BACKGROUND

Although segmentectomy is a widely used surgical procedure, lobectomy is the standard procedure for resectable non-small-cell lung cancer (NSCLC). This study aimed to evaluate the efficacy and safety of segmentectomy for NSCLC up to 3 cm in size, including ground-glass opacity (GGO) and predominant GGO.

METHODS

A multicentre, single-arm, confirmatory phase 3 trial was conducted across 42 institutions (hospitals, university hospitals, and cancer centres) in Japan. Segmentectomy with hilar, interlobar, and intrapulmonary lymph node dissection was performed as protocol surgery for patients with a tumour diameter of up to 3 cm, including GGO and dominant GGO. Eligible patients were those aged 20-79 years with an Eastern Cooperative Oncology Group performance score of 0 or 1 and clinical stage IA tumour confirmed by thin-sliced CT. The primary endpoint was 5-year relapse-free survival (RFS). This study is registered with the University Hospital Medical Information Network Clinical Trials (UMIN000011819), and is ongoing.

FINDINGS

A total of 396 patients were registered from Sept 20, 2013, to Nov 13, 2015, of whom 357 underwent segmentectomy. At a median follow-up of 5·4 years (IQR 5·0-6·0), the 5-year RFS was 98·0% (95% CI 95·9-99·1). This finding exceeded the 87% of the pre-set threshold 5-year RFS and the primary endpoint was met. Grade 3 or 4 early postoperative complications occurred in seven patients (2%), but no grade 5 treatment-related deaths occurred.

INTERPRETATION

Segmentectomy should be considered as part of standard treatment for patients with predominantly GGO NSCLC with a tumour size of 3 cm or less in diameter, including GGO even if it exceeds 2 cm.

FUNDING

National Cancer Centre Research and Development Fund and Japan Agency for Medical Research and Development.

Prospective Radiologic-Pathologic Correlation of Macroscopic Volume and Microscopic Extension of Nonsolid Lung Nodules on Thin-section CT Images for Sublobar Resection and Stereotactic Radiotherapy Planning

INTRODUCTION

The objective of this study was to determine whether computed tomography (CT) could be a useful tool for nonsolid lung nodule (NSN) treatment planning, surgery or stereotactic body radiation therapy (SBRT), by assessing the macroscopic and microscopic extension of these nodules.

METHODS

The study prospectively included 23 patients undergoing anatomic resection at the Foch Hospital in 2020/2021 for NSN with a ground-glass component of more than 50%. Firstly, for each patient, both the macroscopic dimensions of the NSN were assessed on CT and during pathologic analysis. Secondly, the microscopic extension was assessed during pathologic examination. Wilcoxon sign rank tests were used to compare these dimensions. Spearman correlation test and Bland-Altman analysis were used to evaluate the agreement between radiological and pathologic measurements.

RESULTS

On CT, the median largest diameter and volume of NSN were 21 mm and 3780 cc, while on pathologic analysis, they were 15 mm and 1800 cc, respectively. Therefore, the largest diameter and volume of the NSN were significantly higher on CT than on pathological analysis. For microscopic extension, the median largest diameter and volume of NSN were 17 mm and 2040 cc, respectively. No significant difference was observed between the macroscopic size and the microscopic extension assessed during pathologic analysis. Moreover, correlation analysis and Bland-Altman plots showed that radiological and pathologic measurements could provide equivalent precision.

CONCLUSION

Our study showed that CT did not underestimate the macroscopic size and microscopic extension of NSN and confirmed that CT can be used for NSN treatment planning.

Distinct Prognostic Impact of PET Findings Based on Radiological Appearance in Clinical Stage IA Lung Adenocarcinoma

INTRODUCTION

Although solid appearance on computed tomography and positive findings on positron emission tomography (PET) have been both associated with poor outcome in lung adenocarcinoma, the extent to which these findings overlap is unknown. This study aimed to determine the differences in prognostic significance of PET findings in part-solid nodules (PSNs) and solid nodules.

MATERIALS AND METHODS

We retrospectively investigated 417 patients with clinical stage IA adenocarcinoma who underwent curative resection between 2010 and 2017. We compared disease-free survival (DFS), cumulative incidence of disease recurrence (CIR) and clinicopathological characters between PET-positive and negative groups among PSNs and solid nodules, respectively. We used 2.5 as a cut-off value of maximum standardized uptake value (SUV max).

RESULTS

In PSNs (n = 235), PET-positive group (n = 59) showed more aggressive features in several clinicopathological variables, poorer DFS (P < .001) and higher CIR (P < .001) than PET-negative group (n = 176). In contrast, in solid nodules (n = 182), DFS (P = .521) and CIR (P = .311) were not significantly different between PET-positive (n = 128) and negative groups (n = 54). SUV max was proved to be the independent prognostic factor of DFS by multivariate analysis (HR, 1.155; 95% CI, 1.036-1.287) only in PSNs.

CONCLUSION

These findings showed distinct impact on prognosis of PET findings between PSNs and solid nodules. PET-positive finding was more important prognostic factor in PSNs than in solid nodules among clinical stage IA lung adenocarcinoma.

Assessment of preoperative anxiety and depression in patients with pulmonary ground-glass opacities: Risk factors and postoperative outcomes

Objective

A large number of patients with pulmonary ground-glass opacities (GGOs) have anxiety and depression. However, the contributing factors and effects of anxiety and depression on postoperative outcomes are still unclear.

Methods

Clinical data for patients undergoing surgical resection for pulmonary GGOs were collected. We prospectively evaluated levels and risk factors for anxiety and depression in patients with GGOs before surgery. The relationship between psychological disorders and postoperative morbidity was evaluated. Quality of life (QoL) was also assessed.

Results

A total of 133 patients were enrolled. Prevalence rates of preoperative anxiety and depression were 26.3% (n = 35) and 18% (n = 24), respectively. Multivariate analysis revealed depression [odds ratio(OR) = 16.27, p < 0.001] and multiple GGOs (OR = 3.146, p = 0.033) to be risk factors for preoperative anxiety. Anxiety (OR = 52.166, p < 0.001), age > 60 (OR = 3.601, p = 0.036), and unemployment (OR = 8.248, p = 0.006) were identified as risk factors for preoperative depression. Preoperative anxiety and depression were associated with lower QoL and higher postoperative pain scores. Our results also revealed that the incidence of postoperative atrial fibrillation was higher in patients with than in those without anxiety.

Conclusions

In patients with pulmonary GGOs, comprehensive psychological assessment and appropriate management are required before surgery to improve QoL and reduce postoperative morbidity.

The efficacy of a machine learning algorithm for assessing tumour components as a prognostic marker of surgically resected stage IA lung adenocarcinoma

BACKGROUND

The importance of the stromal components in tumour progression has been discussed widely, but their prognostic role in small size tumours with lepidic components is not fully understood. Applying digital tissue image analysis to whole-slide imaging may enhance the accuracy and reproducibility of pathological assessment. This study aimed to evaluate the prognostic value of tumour components of lung adenocarcinoma by measuring the dimensions of the tumour consisting elements separately, using a machine learning algorithm.

METHODS

Between September 2002 and December 2016, 317 patients with surgically resected, pathological stage IA adenocarcinoma with lepidic components were analysed. We assessed the whole tumour area, including the lepidic components, and measured the epithelium, collagen, elastin areas and alveolar air space. We analysed the prognostic impact of each tumour component.

RESULTS

The dimensions of the epithelium and collagen areas were independent significant risk factors for recurrence-free survival (hazard ratio, 8.38; 95% confidence interval, 1.14-61.88; P = 0.037, and hazard ratio, 2.58; 95% confidence interval, 1.14-5.83; P = 0.022, respectively). According to the subgroup analysis when combining the epithelium and collagen areas as risk factors, patients with tumours consisting of both large epithelium and collagen areas showed significantly poor prognoses (P = 0.002).

CONCLUSIONS

We assessed tumour components using a machine learning algorithm to stratify the post-operative prognosis of surgically resected stage IA adenocarcinomas. This method might guide the selection of patients with a high risk of recurrence.

The comparison of Lobe-Specific or Systematic Mediastinal Lymph Node Dissection for Early-Stage Lung Adenocarcinoma With Consolidation Tumor Ratio Over 0.5

INTRODUCTION

Surgery is the most effective treatment for early-stage lung cancer. This study will propose a personalized plan for mediastinal lymph node dissection in early-stage lung adenocarcinoma to reduce the risk of surgery and improve the quality of life.

METHODS

This study retrospectively analyzed the patients underwent lobectomy and lymph node dissection in the Department of Thoracic Surgery, Zhongshan Hospital, Fudan University. Clinical stage I lung adenocarcinoma patients with solid component ratio (CTR) between 0.5 and 1 were included. Patients were divided into systematic (S-MLND) and lobe-specific (L-MLND) mediastinal lymph node dissection groups. The days of hospitalization, the presence or absence of complications, the recurrence-free survival rate, and the overall survival rate were calculated to evaluate the postoperative quality and operation risk of the patients.

RESULTS

210 patients (138 L-MLND and 72 S-MLND) were included. 2 lymph node metastases appeared in the S-MLND group while none in the L-MLND group (P = .049). No differences were shown in age, tumor site, size, solid component, degree of tumor invasion, and stage. The proportion of patients with severe postoperative cough and the length of hospital stay in the L-MLND group decreased. The 5-year OS of the entire cohort was 98.1%, 98.6% in L-MLND, compared with 97.2% in S-MLND; RFS was 94.8%, 95.7% in L-MLND, compared with 93.0% in S-MLND.

CONCLUSION

For cIA lung adenocarcinoma, according to the Thin-slice CT within 1 month before the operation, if the main lesion was less than 3 cm and CTR over 0.5, L-MLND is as effective as S-MLND.

Lepidic growth component as a favorable prognostic factor in non-small cell lung cancer of ≤3 cm

BACKGROUND

Many non-small cell lung cancer (NSCLC) tumors present complex histology with various components. The effects of the lepidic growth component (LGC) on the prognosis of NSCLC have not been investigated. Here, we investigated whether an LGC is a relevant prognostic factor for NSCLC.

METHODS

This study retrospectively investigated the clinicopathologic characteristics of 379 patients with NSCLC ≤3 cm who underwent complete surgical resection between 2004 and 2016 at the University of Yamanashi Hospital. The histologic subtypes were classified into NSCLC with or without an LGC. We evaluated the effect of an LGC on the clinicopathologic features and 5-year overall survival of patients with NSCLC.

RESULTS

On final pathology, 214 (56%) of 379 patients had an LGC, and 165 (44%) did not. Sex, smoking history, ground-glass opacity component, pathologic invasive size, lymph node metastasis, pleural invasion, vessel invasion, pathologic stage, and histologic type were significantly different between the groups. Multivariate analysis of 5-year overall survival, identified age (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.035-1.105; p < 0.001), pathologic invasive size (HR, 1.548; 95% CI, 1.088-2.202; p = 0.015) and LGC (HR, 2.11; 95% CI, 1.099-4.051; p = 0.025) as independent prognostic factors. When the pathologic invasive size was matched, the 5-year overall survival of the LGC and non-LGC groups was 93% and 77%, respectively (p = 0.006).

CONCLUSIONS

LGC is a significantly favorable prognostic factor for NSCLC with a pathologic invasive size of ≤3 cm.

Distinct Prognostic Factors of Ground Glass Opacity and Pure-Solid Lesion in Pathological Stage I Invasive Lung Adenocarcinoma

BACKGROUND

Ground glass opacity (GGO) is associated with favorable survival in lung cancer. However, the relevant evidence of the difference in prognostic factors between GGO and pure-solid nodules for pathological stage I invasive adenocarcinoma (IAC) is limited. We aimed to identify the impact of GGO on survival and find prognostic factor for part-GGO and pure-solid patients.

METHODS

Between December 2007 and August 2018, patients with pathological stage I IAC were retrospectively reviewed and categorized into the pure-GGO, part-GGO, and pure-solid groups. Survival curves were analyzed by the Kaplan-Meier method and compared by log-rank tests. Least absolute shrinkage and selection operator and Cox regression models were used to obtained prognostic factors for disease-free survival (DFS) and overall survival (OS).

RESULTS

The number of patients with pure-GGO, part-GGO, and pure-solid was 134, 540, and 396, respectively. Part-GGO patients with consolidation-tumor-ratio (CTR) > 0.75 had similar outcome to those with pure-solid nodules. In part-GGO patients, CTR was negatively associated with OS (P = 0.007) and solid tumor size (STS) was negatively associated with DFS (P < 0.001). Visceral pleural invasion (VPI) was negatively associated with OS (P = 0.040) and DFS (P = 0.002). Sublobectomy was negatively associated with OS (P = 0.008) and DFS (P = 0.005), while extended N1 stations examination was associated with improved DFS (P = 0.005) in pure-solid patients.

CONCLUSIONS

Though GGO component is a positively prognostic factors of patients with pathological stage I IAC, a small proportion of GGO components is not associated with favorable survival. VPI, STS and CTR are the significant predictors for part-GGO patients. Sublobectomy, especially wedge resection should be used cautiously in pure-solid patients.

Prognostic Impact of Very Small Ground-Glass Opacity Component in Stage IA Solid Predominant Non-small Cell Lung Cancer

We evaluated the prognostic role of the presence of a very small ground glass opacity (GGO) component in stage IA solid-predominant non-small cell lung cancer (NSCLC). We evaluated surgically resected 1471 patients diagnosed with stage IA solid-predominant NSCLC. They were classified into 3 groups; that is, GGO group (0.5 Collapse

Key Words

• Clinical stage IA
• Ground-glass opacity
• Lung cancer
• Prognosis

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MESH Headings

• Humans
• Carcinoma, Non-Small-Cell Lung/mortality
• Carcinoma, Non-Small-Cell Lung/diagnostic imaging
• Carcinoma, Non-Small-Cell Lung/surgery
• Carcinoma, Non-Small-Cell Lung/pathology
• Lung Neoplasms/mortality
• Lung Neoplasms/pathology
• Lung Neoplasms/diagnostic imaging
• Lung Neoplasms/surgery
• Male
• Female
• Neoplasm Staging
• Middle Aged
• Aged
• Pneumonectomy/mortality
• Time Factors
• Risk Factors
• Retrospective Studies
• Predictive Value of Tests
• Risk Assessment
• Tomography, X-Ray Computed
• Adult
• Treatment Outcome
• Aged, 80 and over

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Affiliation(s)

Aritoshi Hattori Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
Takeshi Matsunaga Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan
Mariko Fukui Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan
Kazuhiro Suzuki Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan
Kazuya Takamochi Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan
Kenji Suzuki Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan

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Oncologic outcomes of segmentectomy for stage IA radiological solid-predominant lung cancer >2 cm in maximum tumour size

OBJECTIVES

We aimed to compare the outcomes of segmentectomy with those of lobectomy in clinical-stage IA radiological solid-predominant non-small-cell lung cancer (NSCLC) >2 cm in maximum tumour size.

METHODS

A retrospective review was performed for radiological solid-predominant NSCLC >2-3 cm in maximum tumour size with a ground-glass opacity component on thin-section computed tomography. Multivariable or propensity score-matched analyses were performed to control for confounders for survival. Overall survival (OS) was analysed using a Kaplan-Meier estimation.

RESULTS

Of the 215 eligible cases, segmentectomy and lobectomy were performed in 46 and 169 patients. Multivariable analysis revealed that standardized uptake value (hazard ratio: 1.148, 95% confidence interval: 1.032-1.276, P = 0.011) was an independently significant prognosticators of OS, while the operative mode was not associated (hazard ratio: 0.635, 95% confidence interval: 0.132-3.049, P = 0.570). The 5 y-OS was excellent and did not differ significantly between segmentectomy and lobectomy (95.5% vs 90.2%; P = 0.697), which was also shown in the propensity score analysis (96.8% vs 94.0%; P = 0.406), with a median follow-up time of 5.2 years. Locoregional recurrence was found in 2 (4.3%) segmentectomy and 13 (7.7%) lobectomy (P = 0.443). In the subgroup analysis stratified by solid component size, the 5 y-OS was similar between segmentectomy and lobectomy in the c-T1b and c-T1c groups, respectively [c-T1b (n = 163): 94.1% vs 91.8%; P = 0.887 and c-T1c (n = 52): 100% vs 84.9%; P = 0.197].

CONCLUSIONS

Segmentectomy showed similar oncological results compared to lobectomy in solid-predominant NSCLC with a ground-glass opacity component >2-3 cm in maximum tumour size. More prospective randomized trials are needed to adequately expand the indication of anatomic segmentectomy for early-stage NSCLC.

Clinical features and surgical outcomes of young patients with lung adenocarcinoma manifesting as ground glass opacity

Background

More and more ground glass opacity associated lung adenocarcinoma (GGO-LUAD) have been diagnosed in young patients nowadays. Our study aims to investigate the clinical features and surgical outcomes of young patients with GGO-LUAD.

Methods

Patients aged ≤ 40 years who were diagnosed as lung adenocarcinoma and who underwent video assisted thoracoscopic surgery (VATS) were retrospectively reviewed from January 2017 to December 2018. According to radiological appearance of the patient’s lesions, they were divided into a solid nodule (SN) group and GGO group. The pathological subtypes, surgical procedures and nodules size were analyzed, and the clinical features and prognosis were evaluated between these patients.

Results

A total of 165 patients were included, of which 133 were in the GGO group and 32 in the SN group. Both the GGO group and the SN group had a higher proportion of females and non-smokers. Compared with patients (15.63%) in the SN group, there are more patients (27.8%) under the age of 30 in the GGO group. Pathological findings showed 83.5% of lesions were pre-invasive lesions in the GGO group, although 16.5% of lesions were invasive adenocarcinoma, whereas in the SN group, 96.9% were invasive adenocarcinoma. The GGO group had significantly better histological characteristics and prognosis than the SN group. Perioperative complications occurred in only 6 patients, including pneumonia in one patient, pneumothorax in two patients, and prolonged air leak in three patients. No other serious complications or deaths occurred. After a median follow-up time of 41.2 ± 7.2 months (32-56), the 3-year recurrence free survival (RFS) (100%) and overall survival (OS) (100%) of the GGO group were significantly higher than those (93.42% and 96.88%) in the SN group.

Conclusions

Young patients with GGO-LUAD are mainly non-smokers and female. Most of these patients were early-stage with good prognosis after surgery.

Aggressive histological component in subsolid lung adenocarcinoma: priority for resection without delay

INTRODUCTION

This study explored the predictors of a histological aggressive component in ground glass opacity-containing lung adenocarcinoma.

METHODS

Of the 2388 patients who underwent resection for lung cancer at our institute between 2017 and 2020, we collected data on the 501 patients with ground glass opacity-containing adenocarcinoma with a total diameter of ≤2 cm. Using a historical cohort, we identified histological aggressive components that were related to a poor prognosis in early-stage adenocarcinoma. A multivariable analysis was conducted to identify predictors for the presence of a histological aggressive component.

RESULTS

Lymphovascular invasion and predominant micropapillary or solid patterns were identified as histological aggressive components by a prognostic analysis using a historical cohort. Of the 501 patients included, 36 (7.2%) had at least one histological aggressive component. A multivariate analysis showed that a consolidation/tumour ratio > 0.5 (P < 0.01), maximum standardized uptake value on positron emission tomography ≥1.5 (P = 0.01) and smoking index >20 pack-years (P = 0.01) were predictors of the presence of a histological aggressive component. A total of 98% of cases without any of the above factors did not have a histological aggressive component.

CONCLUSIONS

Approximately 7% of ground glass opacity-containing small adenocarcinomas contained histological aggressive component. A consolidation/tumour ratio > 0.5, maximum standardized uptake value ≥ 1.5 and smoking index >20 pack-years were predictors for such cases. These predictors may be useful for screening patients with a potentially high risk of a poor prognosis and for prioritizing resection without delay.

Impact of a Ground-glass Opacity Component on c-Stage IA Lung Adenocarcinoma

Studies have shown that tumors with ground-glass opacity (GGO) components are associated with favorable outcomes. However, this view should be confirmed in an international cohort. We aimed to verify the impact of a GGO component on clinical (c)-stage IA lung adenocarcinoma and to describe the biological discrepancies between the part-solid and pure-solid groups. We evaluated 1333 cases of surgically resected c-stage IA lung adenocarcinomas, including 484 part-solid and 849 pure-solid tumors. Furthermore, we matched the solid size between the 2 groups and examined 470 patients. We compared the prognoses between the 2 groups before and after matching. The prognostic and biological differences were described before and after matching. Compared with the pure-solid group, the part-solid group was associated with favorable outcomes [5-year overall survival (OS) 99.4% vs 87.6%, P < 0.001; 5-year recurrence-free survival (RFS) 96.9% vs 82.2%, P < 0.001]. Similar results were obtained after matching (5-year OS 98.9% vs 92.2%, P = 0.012; 5-year RFS 95.0% vs 88.5%, P = 0.007). Multivariable analyses revealed that GGO component appearance was a factor of better OS and RFS. The part-solid tumor, regardless of the size of the solid component, had a similar outcome to the pure-solid tumor of c-stage T1a classification. Also, more epidermal growth factor receptor, human epidermal growth factor receptor-2 mutations, and receptor tyrosine kinase ROS-1-positive were observed in the part-solid group. In comparison, more wild types and Kirsten-Ras were observed in the pure-solid group. Adenocarcinomas with a GGO component were associated with superior outcomes. The GGO component should be considereda new clinical T descriptor. Early-stage lung adenocarcinomas with and without a GGO component may be 2 distinct tumor types.

Histopathologic Basis for a Chest CT Deep Learning Survival Prediction Model in Patients with Lung Adenocarcinoma

Background A preoperative CT-based deep learning (DL) prediction model was proposed to estimate disease-free survival in patients with resected lung adenocarcinoma. However, the black-box nature of DL hinders interpretation of its results. Purpose To provide histopathologic evidence underpinning the DL survival prediction model and to demonstrate the feasibility of the model in identifying patients with histopathologic risk factors through unsupervised clustering and a series of regression analyses. Materials and Methods For this retrospective study, data from patients who underwent curative resection for lung adenocarcinoma without neoadjuvant therapy from January 2016 to September 2020 were collected from a tertiary care center. Seven histopathologic risk factors for the resected adenocarcinoma were documented: the aggressive adenocarcinoma subtype (cribriform, morular, solid, or micropapillary-predominant subtype); mediastinal nodal metastasis (pN2); presence of lymphatic, venous, and perineural invasion; visceral pleural invasion (VPI); and EGFR mutation status. Unsupervised clustering using 80 DL model-driven CT features was performed, and associations between the patient clusters and the histopathologic features were analyzed. Multivariable regression analyses were performed to investigate the added value of the DL model output to the semantic CT features (clinical T category and radiologic nodule type [ie, solid or subsolid]) for histopathologic associations. Results A total of 1667 patients (median age, 64 years [IQR, 57-71 years]; 975 women) were evaluated. Unsupervised patient clusters 3 and 4 were associated with all histopathologic risk factors (P < .01) except for EGFR mutation status (P = .30 for cluster 3). After multivariable adjustment, model output was associated with the aggressive adenocarcinoma subtype (odds ratio [OR], 1.03; 95% CI: 1.002, 1.05; P = .03), venous invasion (OR, 1.03; 95% CI: 1.004, 1.06; P = .02), and VPI (OR, 1.08; 95% CI: 1.06, 1.10; P < .001), independently of the semantic CT features. Conclusion The deep learning model extracted CT imaging surrogates for the histopathologic profiles of lung adenocarcinoma. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Yanagawa in this issue.

A Novel Radiopathological Grading System to Tailor Recurrence Risk for Pathologic Stage IA Lung Adenocarcinoma

To validate the efficiency of pathologic grading system in pathologic stage IA lung adenocarcinoma (LUAD), and explore whether integrating preoperative radiological features would enhance the performance of recurrence discrimination. We retrospectively collected 510 patients with resected stage IA LUAD between January 2012 and December 2019 from Guangdong Provincial People's Hospital (GDPH). Pathologic grade classification of each case was based on the International Association for the Study of Lung Cancer (IASLC) pathologic staging system. Kaplan-Meier curves was used to assess the power of recurrence stratification. Concordance index (C-Index) and receiver operating characteristic curves (ROC) were used for evaluating the clinical utility of different grading systems for recurrence discrimination. Patients of lower IASLC grade showed improved recurrence-free survival (RFS) (P < 0.0001) where numerically difference was found between grade II and grade III (P = 0.119). By integrating the IASLC grading system and radiological feature, we found the RFS rate decreased as the novel radiopathological (RP) grading system increased (P < 0.0001). The difference of RFS curves between any 2 groups as per the RP grading system was statisticallysignificant (RP grade I vs RP grade II, p = 0.007; RP grade I vs RP grade III, P < 0.0001; RP grade II vs RP grade III, P = 0.0003). Compared with the IASLC grading system, the RP grading system remarkably improved recurrence survival discrimination (C-index: 0.822; area under the curve, 0.845). Integrating imaging features into pathologic grading system enhanced the efficiency of recurrence discrimination for resected stage IA LUAD and might help conduct subsequent management.

Limited resection for stage IA radiologically invasive lung cancer: a real-world nationwide database study

OBJECTIVES

Radiologically invasive non-small cell lung cancer, defined as consolidation size to maximum tumour diameter ratio of over 0.5, is associated with pathological invasiveness and worse prognosis. However, there are no real-world, nationwide database studies on limited resections that consider radiological invasiveness. This study aimed to investigate the prognostic validity of limited resection, such as segmentectomy and wedge resection, in cStage IA (TNM 8th edition) radiologically invasive lung cancer.

METHODS

We conducted a retrospective analysis of patients who underwent complete resection according to the Japanese Joint Committee of Lung Cancer Registry Database. The relationship between surgical procedures and prognosis was examined using stratification by cT factor and radiological invasiveness.

RESULTS

Among the 5,692 patients enrolled, lobectomy, segmentectomy, and wedge resection were performed in 4,323 (80.0%), 657 (11.5%), and 712 (12.5%) patients, respectively. Multivariable analysis with or without propensity score matching indicated that older age, poor performance status, and wedge resection were significantly associated with worse prognosis and that patients who underwent segmentectomy showed an equivalent prognosis to those who underwent lobectomy. Subset analyses revealed that segmentectomy showed an equivalent prognosis to lobectomy in patients with cT1b or less, but not in those with cT1c, especially for non-pure radiological invasive cT1c; 5-year overall survival rates were 91.4% vs 90.4% in cT1b with non-pure radiological invasiveness, and 80.0% vs 83.8% in cT1b with pure radiological invasiveness, respectively.

CONCLUSIONS

Segmentectomy can be an alternative to lobectomy in patients with radiologically invasive lung cancer with cT1b or less, but not in those with cT1c.

Radiological classification, gene-mutation status, and surgical prognosis of synchronous multiple primary lung cancer

OBJECTIVE

To investigate the radiological classification, gene-mutation status, and surgical prognosis of synchronous multiple primary lung cancer (sMPLC).

METHODS

From January 2013 to October 2019, 192 consecutive patients with sMPLC were investigated. The clinical, CT, molecular, and pathological features of all patients were analyzed. Furthermore, the prognosis of 89 patients who only underwent surgical resection was evaluated.

RESULTS

Among 192 patients, all lesions pathologically confirmed or highly suspected as tumors based on radiological findings were retrospectively analyzed, and the CT findings of sMPLC were classified into three types: (I) all lesions manifested as solid nodules/masses (14.06%, 27/192), (II) all lesions manifested as subsolid nodules/masses (43.23%, 83/192), and (III) tumor lesions manifested as a combination of ≥ 2 of the following patterns: solid nodules/masses, subsolid nodules/masses, cystic airspace, and focal consolidation (42.71%, 82/192). For 252 tumors undergoing epidermal growth factor receptor (EGFR)-mutation testing, the EGFR-mutation rate was higher in subsolid tumors than that in solid tumors (p < 0.05). Among 19 patients with all tumors undergoing surgery and driver-gene testing, genetic heterogeneity was prevalent among the multiple tumors (63.16%,12/19). The highest clinical stage of non-I, ipsilateral distribution of tumors, and CT classification of I indicated a poor prognosis for patients with sMPLC (all p < 0.05).

CONCLUSION

Subsolid lesions are the most common presentation of sMPLC. Genetic heterogeneity in driver mutations among sMPLC may be present. Prognosis in patients with sMPLC is determined by the highest clinical TNM stage, distribution, and radiological classification among the multiple tumors.

KEY POINTS

• Synchronous multiple primary lung cancer (sMPLC) has three types of CT findings. • Genetic heterogeneity may be prevalent among the multiple tumors. • Prognosis in patients with sMPLC is associated with the highest clinical TNM stage, distribution, and radiological classification among the multiple tumors.

Preoperative Patient and Lesion Features Are Valuable for Predicting the Prognosis of Resectable Peripheral Non-Small Cell Lung Cancer

OBJECTIVE

The aim of the study was to investigate the preoperative factors affecting the survival of patients with resectable peripheral non-small cell lung cancer (NSCLC) to improve the management of NSCLC.

METHODS

One hundred ninety-nine patients with peripheral NSCLC diagnosed clinically without lymph node metastasis were enrolled. The preoperative computed tomography characteristics of the tumors were retrospectively analyzed and the preoperative clinical data were collected. The size of the solid components for lung adenocarcinomas containing ground-glass opacity (GGO) component were measured. Kaplan-Meier method with log-rank test was used to compare overall survival (OS) between groups. Univariate and multivariate cox regression analyses were used to identify prognostic factors.

RESULTS

Survival analysis showed that the OS of the group with a tumor of 3 cm or less was longer than that of the group with a tumor greater than 3 cm, the OS of the group with GGO component was superior to that of the group without GGO component, and the OS of the group with elevated carcinoembryonic antigen (CEA) levels was inferior to that of the group with normal CEA levels. Multivariate Cox regression analysis showed that tumor size, density, and preoperative CEA level were independent factors affecting OS, with hazard ratios of 2.401, 0.457, and 1.948, respectively. The analysis of lung adenocarcinomas with GGO component demonstrated that the mean size of the solid component in the nonsurviving group was significantly larger than that in the surviving group (mean, 23 ± 6.4 vs 8.6 ± 7.0 mm). The area under the receiver operating characteristic curve of the solid component size of lung cancer containing GGO component to predict postoperative death was 0.932.

CONCLUSIONS

Tumor size, density, and preoperative CEA level were independent prognostic factors of patients with resectable peripheral NSCLCs. Preoperative computed tomography findings can be valuable for predicting the prognosis of patients with NSCLC after surgery.

Presence of a Ground-glass Opacity Component is the True Prognostic Determinant in Clinical Stage I Non-Small Cell Lung Cancer

Introduction

Recent studies have suggested that including presence or absence of ground-glass opacity (GGO) may improve the tumor descriptor (T descriptor) classification in clinical stage I NSCLC. In this study, we analyzed prognostic implications of presence or absence of GGO, size of the solid component, and predominant histology to identify the true prognostic determinant for early-stage NSCLC.

Methods

We retrospectively examined 384 patients with clinical stage I NSCLC (solid: 242, part solid: 142) who underwent complete resection between 2009 and 2013.

Results

Survival curves of the whole cohort revealed good separation using the current TNM classification. Nevertheless, the part-solid group had a favorable prognosis irrespective of solid component size. Conversely, patients in the solid tumor group with tumors between 3 and 4 cm had a worse prognosis than patients whose tumors were less than or equal to 3 cm. Thus, we propose the following novel T descriptor classification: IA, part-solid tumors; IB, solid tumors less than or equal to 3 cm; and IC, solid tumors between 3 and 4 cm. This novel classification system stratified patient prognosis better than the current classification. On pathologic evaluation, the part-solid group always had better prognoses than the solid group in each subgroup divided by pathologic grade.

Conclusions

These results suggest that presence of GGO is the true prognostic determinant of stage I NSCLC, irrespective of the size of the solid component. Our novel T descriptor classification system could more accurately predict prognoses of clinical stage I NSCLC cases.